import numpy as np
arr = np.array([[1,2,3,4],[5,6,7,8],[9,10,11,12]])
# print(arr[1,2])
# print(arr[1:3,1:3])
# print(arr[1,::2])
# print(arr[::2,:3])


print(arr[[1,0,2]])
print(arr[[0,1,2],[1,3,2]])